Apical cytoplasm

About: Apical cytoplasm is a research topic. Over the lifetime, 1080 publications have been published within this topic receiving 36131 citations.

Effects of Hexachlorobenzene on Rat Renal Cortex: An Ultrastructural Study

Abstract: Male Wistar albino rats, bred and fed under standard laboratory conditions, were administered for 20 days two dosages (Group I: 750 mg/kg body weight (n = 15) and Group II: 1500 mg/kg body weight (n = 15)) of oral hexachlorobenzene resolved in corn oil. Control group animals (n = 15) received only corn oil for 20 days. Twenty-four hours after the administration of the last dose, renal tissue samples, obtained by laparotomy, were fixed in 3% glutaraldehyde in phosphate buffer and 1% aqueous osmium tetroxide. Following the routine tissue processing steps, samples were blocked in Araldyte CY 212. Ultrathin sections taken by LKB V ultratome were stained with uranyl acetate-lead citrate and evaluated under a JEOL 100C transmission electron microscope. In experimental group I, glomerular features were dilated and hyperaemic capillaries, discontinuous endothelial fenestrae, ondulated and thickened basement membrane in some areas and discontinuous podocyte pedicels were observed. The proximal tubular features had irregular intracytoplasmic foldings and myelin figures in basal and apical cellular regions, whereas distal tubular cells had large, pleomorphic and electron dense mitochondria, microvillous loss and an apical cytoplasm projecting into the tubular lumen. In experimental group II, renal cortical features revealed irregularly arranged glomerular capillaries which had an ondulated and thickened basement membrane, degenerative endothelial cell fenestrae and irregularities in podocyte pedicels. The proximal tubular cells of the same group contained different size vacuoles with myelin figure-like structures, and giant vacuoles were also present within these cells. Microvilli of the distal tubular cells projecting into the lumen were absent in some regions. There was increased vascularization in the interstitial region and these dilated blood vessels seemed to invade almost the whole intertubular area. In conclusion, hexachlorobenzene administration might have adverse effects on renal tissue and these effects become worse with increased dosages of the agent.

An unusual parotid gland in the tent‐building bat, Uroderma bilobatum: Possible correlation of interspecific ultrastructural differences with differences in salivary pH and buffering capacity

Abstract: The tent-building bat, Uroderma bilobatum, is a small, frugivorous phyllostomid bat with a broad neotropical distribution. Generally found in humid forest, this bat lives in small groups that create daytime ‘‘roosts’’ from large leaves of a variety of tropical plants. Fruit eating engenders a variety of ecological and physiological challenges for bats, some of which could require adaptive features in their salivary glands. The parotid salivary glands of Uroderma bilobatum were prepared for transmission electron microscopy by using methods that have become standard for field work. The parotid gland is extremely unusual in structure. Although the secretory endpieces still produce serous granules with a complex substructure, they are modified into quasi striated ducts. Their basal folds, which are extensive, occasionally harbor some vertically oriented mitochondria, imparting a resemblance to striated ducts. Other evidence for the endpiece origin of these parenchymal components is a well-developed system of intercellular canaliculi, structures that never occur in bona fide striated ducts. The long but sparse intercalated ducts consist of two types of cells, each of which elaborates a modest number of secretory granules of differing substructure. Striated ducts are of conventional morphology, except that a few dark cells shaped like wine glasses are present in their walls. The striated duct cells produce no secretory granules, but their apical cytoplasm may contain some small, empty vesicles. Capillaries lie in longitudinal grooves in the base of the duct cells, an arrangement that might enhance electrolyte exchange. Excretory ducts consist of simple cuboidal epithelium composed of cytologically unspecialized cells that sometimes includes a dark cell. It was concluded that salivary glands could have a major role in adapting species to acquire nutrients from marginal sources, such as tropical fruits, which have a low protein and sodium content. The unusual parotid acinar cells in Uroderma bilobatum are discussed in the context of salivary pH and buffering capacity. Comparisons are made with four other bat species, including an insectivorous species with a salivary pH .

The studies on the ultrastructure of proventriculus and gizzard in bustard

Abstract: Objective To provide the theoretical basis for artificially breeding of bustard, the ultrastructures of the proventriculus and the gizzard of bustard were studied. Method The ultrathin sections were observed under transmission electron microscope. Results There were various size of vacuoles around nucleus and a lot of dark granules about 0\^2～0\^8?μm in diameter in the apical cytoplasm of the columnar epithelium of the mucosa. The epithelium of the inner cavity of papilla consisted of the columnar mucous cells with a dense flat nucleus were occupied with a lot of mucin granules. The proventricular glandular epithelium can be divided into two types based on the differences between the shape of nucleus and structural features of mitochondria. Many granules occupied the apical cytoplasm and a spherical or oval nucleus located in the basal region of the gizzard glandular cell. Two cell types can be differentiated on the basis of the structure of secretive granules, homogeneous and fibrous. The secretion of both types of cells participated in formation of the keratin lining. The ultrastructure of the lining varied from basal region of gizzard gland to the mucosal surface. Conclusion These results suggested that the bustard possess much stronger digestive capability.

Sertoliform endometrioid tumor of ovary presenting as torsion

Abstract: Sertoliform endometrioid carcinoma of the ovary (SEC) is an uncommon variant that bears histologic similarity to sertoli and sertoli-leydig cell tumors. We report an interesting case of SEC in a 55-year-old female with a left ovarian mass with torsion. Histology revealed an SEC, featuring foci of typical endometrioid carcinoma, and areas composed of uniform, small, hollow tubules lined by columnar cells with apical cytoplasm. Tumor cells were strongly immunoreactive for EMA and cytokeratin but negative for inhibin; thus, confirming the diagnosis of SEC ovary. Recognition of this tumor is important as it is a well-differentiated, low-grade malignancy that displays good prognosis when confined to the ovary.

Effects of luxabendazole on the tegument of Fasciola hepatica.

Abstract: The effects in vivo of 5, 10, and 20 mg/kg of luxabendazole (LBZ) on the tegument of Fasciola hepatica have been examined 48 h, 7 days and 14 days post-treatment of experimentally-infected rats. As early as 48 h post-treatment, the drug is shown to provoke significant damage to the tegument. The pathological phenomena characterizing LBZ damage are blebbing of the apical plasmalemma, formation of microvillus-like projections over the free surface, swelling of the basal infolds and stimulation of autophagy. The spines are often fractured; the tegument in the vicinity of spines seems more strongly altered than that in other foci. The basal layer is often changed, from increase of electron density to lack of integrity with the apical cytoplasm. The progress of the ultrastructural damage with time is not expressed. However, cytochemical data show that at longer post-treatment intervals the surface-coat structure becomes irregular and patches of ruthenium red positive material of variable thickness are focally accumulated. Only a slight dose-effect is noted 48 h after LBZ application when the alterations provoked by 5 mg/kg are less evident than those by 10 and 20 mg/kg.